motormount angle, horizontal or angled....taking a poll.

[yurkanip]

I am curious what motormount/drive shaft angles (if any) you are running on various boats, hydro, mono, rigger etc using flex shafts. I have tried both flat (horizontal) mounted, with a slight bend, as it comes to the coupler, then a bend below where it exits the hull basically an s-bend as the euro guys run. Have heard that it takes away any "whip" that results in high rpm setups. I have also run a straight thru the hull (angled motor mount), then the only bend is to meet up with the strut. Still undecided which is "better".

Let me know what you are all running. and WHY.

Thanks

 

[Boris Mazor]

I am curious what motormount/drive shaft angles (if any) you are running on various boats, hydro, mono, rigger etc using flex shafts. I have tried both flat (horizontal) mounted, with a slight bend, as it comes to the coupler, then a bend below where it exits the hull basically an s-bend as the euro guys run. Have heard that it takes away any "whip" that results in high rpm setups. I have also run a straight thru the hull (angled motor mount), then the only bend is to meet up with the strut. Still undecided which is "better".
Let me know what you are all running. and WHY.

Thanks

This is an easy answer to “WHAT”, but mach harder to “WAY”

This is only my personal preferences for flex shaft drive with welded strut and round coupler:

1. The strut not needs any angle, if your boat has proper CG for racing condition of the water.

2. If you need any angle on the strut perhaps are some mistakes in the hall.

3. Motor mount angle (the motor shaft angle) depends of hall type. The angle will be bigger on deep-V mono (up to 10 degrees), and smaller on all flat bottom halls.

4. The drive line should to be a little curved (to properly accept axial load with out increasing friction) with radius over 200 times flex shaft diameter. The front part of drive line has to be straight 5-6” (easier to mount).

Boris

 

[yurkanip]

Thanks boris....I think I understand your logic...I appreciate the input. Anyone else have any input...over 100 views on this thread, someone else has to have some thoughts on this subject. ?

Patrick

 

[Jeff Cowey]

I'm no expert by any means... I mount my engines on an angle for the simple reason to avoid an "s" bend in the flex shaft. In my experience "s" bends in the flex self destruct. Heavy binding at high rpm.

 

[Chris Wood]

s bend is the only way to go.. works great.. all my boat kits i sell come with the s-bend drive line glued in place. been doing it for 5yrs no issues and stu's crapshooters have been using it for alot longer than i have without issue.

the cable busting is due to lack of lube.. not due to bending.

on the motor mount i run them flat.. not angled.. i feel it gets the motor lower in the boat and brings the center of gravity lower.. personal opinon

chris

 

[toyotatruckin]

--- the cable will run smoother in an s-bent tube---

 

[yurkanip]

s bend is the only way to go.. works great.. all my boat kits i sell come with the s-bend drive line glued in place. been doing it for 5yrs no issues and stu's crapshooters have been using it for alot longer than i have without issue.
the cable busting is due to lack of lube.. not due to bending.

on the motor mount i run them flat.. not angled.. i feel it gets the motor lower in the boat and brings the center of gravity lower.. personal opinon

chris

Wood, thanks and intersting theory..I have heard that before of the "s" bend setups. particularly the hull in question of mine is a 30" rigger and a flat motor would actually be a better fit. However...I am using the stuffing box, (glued into the hull) then the stuffing tube going through that, so it can be replaced. Big question now, is how do I do a stuffingbox, stuffing tube setup...and be able to replace the stuffing tube. if I read your response correctly, the tube makes its bend, after an inch or two away from teh motor/coupler...correct? if thats the case, I won't be able to use a replaceable "s" bend stuffing tube, inside a straight stuffing box, glued thru the hull.....thats where I am a little confused...

Thanks and hope to hear your, and others response

Patrick

 

[Greg Hahn]

s bend is the only way to go.. works great.. all my boat kits i sell come with the s-bend drive line glued in place. been doing it for 5yrs no issues and stu's crapshooters have been using it for alot longer than i have without issue.
the cable busting is due to lack of lube.. not due to bending.

on the motor mount i run them flat.. not angled.. i feel it gets the motor lower in the boat and brings the center of gravity lower.. personal opinon

chris

Wood, thanks and intersting theory..I have heard that before of the "s" bend setups. particularly the hull in question of mine is a 30" rigger and a flat motor would actually be a better fit. However...I am using the stuffing box, (glued into the hull) then the stuffing tube going through that, so it can be replaced. Big question now, is how do I do a stuffingbox, stuffing tube setup...and be able to replace the stuffing tube. if I read your response correctly, the tube makes its bend, after an inch or two away from teh motor/coupler...correct? if thats the case, I won't be able to use a replaceable "s" bend stuffing tube, inside a straight stuffing box, glued thru the hull.....thats where I am a little confused...

Thanks and hope to hear your, and others response

Patrick

Make the outer tube from the collett to just below the hull bottom. Bend in a shallow arc one direction all the way up. With that set up the inner tube only must bend one way, then the "S" bend will be out the bottom towards the strut and not inside the outer tube. If you make the ark shallow there's no problem in pushing the inner tube in place. One tip here is to lightly champher the outer edge of the inner tube so it won't gouge the outer tube and will slide easier.

hope this makes sence, without a photo it's tough to explain.

Greg

 

[steve wood]

just lube up the inner tube and twist her in. make the tube longer so you can bend the end over or grab it with a pair of vise grips. after its in place cut off the extra length. you usually can't re use the inner tube if you have to take it out. just keep some spare tubing around

 

[yurkanip]

s bend is the only way to go.. works great.. all my boat kits i sell come with the s-bend drive line glued in place. been doing it for 5yrs no issues and stu's crapshooters have been using it for alot longer than i have without issue.
the cable busting is due to lack of lube.. not due to bending.

on the motor mount i run them flat.. not angled.. i feel it gets the motor lower in the boat and brings the center of gravity lower.. personal opinon

chris

Wood, thanks and intersting theory..I have heard that before of the "s" bend setups. particularly the hull in question of mine is a 30" rigger and a flat motor would actually be a better fit. However...I am using the stuffing box, (glued into the hull) then the stuffing tube going through that, so it can be replaced. Big question now, is how do I do a stuffingbox, stuffing tube setup...and be able to replace the stuffing tube. if I read your response correctly, the tube makes its bend, after an inch or two away from teh motor/coupler...correct? if thats the case, I won't be able to use a replaceable "s" bend stuffing tube, inside a straight stuffing box, glued thru the hull.....thats where I am a little confused...

Thanks and hope to hear your, and others response

Patrick

Make the outer tube from the collett to just below the hull bottom. Bend in a shallow arc one direction all the way up. With that set up the inner tube only must bend one way, then the "S" bend will be out the bottom towards the strut and not inside the outer tube. If you make the ark shallow there's no problem in pushing the inner tube in place. One tip here is to lightly champher the outer edge of the inner tube so it won't gouge the outer tube and will slide easier.

hope this makes sence, without a photo it's tough to explain.

Greg

GReg, thanks. so if I am reading this correctly....the stuffing BOX (short outer stub glued into hull) has a slight bend to it...it is not completely straight, correct? Then the inner tube, the stuffing tube will go through this, up the hull bottom to teh motor collet? and the S bend will be only out the bottom? OR the stuffing tube, itself is the s bend...and only a short section of it is straight, which is where it passes through the stuffing box, which is glued to the hull. ? this is what I gathered from your exlanation. By any chance, any drawings you could attach, or sorts on microsoft-paint, or?

Thanks

 

[Jerry T]

Chris is right, S bend with the motor lower in the hull, lube the cable with an oiler filled with castor or synthetic oil.

If you need an oiler get one from Chris.

My 2¢

 

[Rigged]

I'm no expert by any means... I mount my engines on an angle for the simple reason to avoid an "s" bend in the flex shaft. In my experience "s" bends in the flex self destruct. Heavy binding at high rpm.

I try to use an S bend whenever possible...have NEVER had a shaft break in a boat i setup with an S-bend.

 

[Chris Wood]

Wood, thanks and intersting theory..I have heard that before of the "s" bend setups. particularly the hull in question of mine is a 30" rigger and a flat motor would actually be a better fit. However...I am using the stuffing box, (glued into the hull) then the stuffing tube going through that, so it can be replaced. Big question now, is how do I do a stuffingbox, stuffing tube setup...and be able to replace the stuffing tube. if I read your response correctly, the tube makes its bend, after an inch or two away from teh motor/coupler...correct? if thats the case, I won't be able to use a replaceable "s" bend stuffing tube, inside a straight stuffing box, glued thru the hull.....thats where I am a little confused...

Thanks and hope to hear your, and others response

Patrick

Patrick.

if i am reading this right you are wanting to be able to replace the main tube glued in?? man if that gets damaged odd's are the boat aint worth saving at that point lol.. if i am wrong let me know.. but you can replace the tube that goes inside the s-bend tube.. sand it down with some 400.. get a LONG pc bend a 90degree fold on the end and spray w-40 or tranny fluid on it and twist and push.. small 20 size or smaller are easy.. the bigger ones like 1/4 cable tubes can be a bear.

chris

 

[yurkanip]

Wood,

well, the stuffing box would be glued, and the stuffing tube is what the flex will ride ine, with no teflon. I wanted to be able to replace the stuffing tube inside, of the glued tube. I think I can get this slight bend thru the straight, stuffing box since it will be such a short section of straight...the smaller tube going through it inside..should be able to fit the s bends. I think this is my problem, solved...after reading all of your comments.

Thanks again

Patrick

 

[Scott Schneider]

Issues within boat "Style" that create specific set ups ....

Cats & Monos drive shafts are typically quite short requiring a tilted motor and simple single bend in stuffing tube.

Sport & Rigger hydro drive shaft are typically quite long. Also the distance under the hull/tub drive runs is pretty close to the bottom, so a very shallow engine angle or flat angle can be used.

IMO, Ideal angle on sport/riggers is one that allows tube to exit bottom, get bent back up towards hull bottom, then back down a tad, then straightened out to align with strut. This wavy "S" is what takes the whip out.

Short drives like those in Cats & Monos typically don't whip much if any.

*Avoid having stuffing tube exit bottom of hull/tub and go DEEPER than the air gap distance hull runs above the water at planing attitude. Doing so causes excessive water drag on the stuffing tube at planing speed.

Engines mounted "FLAT" do have the lower C/G, but are not able to be set up with "Tube in Tube" (stuffing tube running in a threw hull pilot tube) These style stuffing tubes with flat angle mounted engines need to be glued/epoxied into the hull as a semi-permanent install.

 

[Chris Wood]

scott,

my engine mounts are flat in my boat kits and i run a tube inside a tube?

chris

 

[opio]

Engines mounted "FLAT" do have the lower C/G, but are not able to be set up with "Tube in Tube" (stuffing tube running in a threw hull pilot tube) These style stuffing tubes with flat angle mounted engines need to be glued/epoxied into the hull as a semi-permanent install.

i don't understand why you could not have a stuffing tube set up with a flat motor mount?

 

[Scott Schneider]

scott,
my engine mounts are flat in my boat kits and i run a tube inside a tube?

chris

Chris then I must be missing something ?

An engine that has it's output mounted parallel to hulls bottom has too have stuffing tube bend down and out the bottom at some point, So how do you do this as a slip "Tube in Tube" :huh:

Pictures perhaps ?

 

[Terry Keeley]

Been runnin' S bend for 15 years now after Gary Preusse mentioned Ed Hughey did some testing with his electrics and found less drag. Haven't twisted a shaft since.

I glue 1/2 the "S" in the hull from the motor to hull bottom using next size up tube, put a gentle bend in the inner tube to match, lube with o-ring lube (shaft grease works too) and slid it right in. Then bend up the inner tube with the strut to for the 2nd half of the "S".

 

[yurkanip]

Terry Keeley, Thank you very much....your pic, and description is exactly what I was trying to describe...and knew it could be done, just needed a clear pic of the prpcedure. Thanks again. My rigger will have a new drive soon, thanks to you.

I really appreciate all of the other posts on her from you all, its great to hear thoughts and experiences in building boats from everyone!

Patrick